This core centralizes and integrates biostatistical services in order to assure timely access and coordinated data collection, editing, and analysis. This team approach facilitates optimum study design and analysis by efficiently organizing the skills of all relevant professional and paramedical personnel. Other administrative activities, such as secretarial and publication services, and professional travel, are also centralized within this Core for more effective management. The core will also provide part-time personnel to maintain a computer system linking the project together and performing complex functions such as scheduling of patients and tests, identifying and maintaining records of use of frozen stored samples, etc. It also will provide logistical personnel for collecting, separating, and storing of serum samples and collecting skeletal bone waste for use in the bone culture studies, and secretarial and other general support items.